Refactor(backend): improve formatting in services, repositories & tests

- Consistently format multi-line function headers, exception handling, and repository method calls for readability.
- Reorganize misplaced imports across modules (e.g., services & tests) into proper sorted order.
- Adjust indentation, line breaks, and spacing inconsistencies in tests and migration files.
- Cleanup unnecessary trailing newlines and reorganize `__all__` declarations for consistency.

backend/app/init_db.py

@@ -16,10 +16,10 @@ from sqlalchemy import select, text
 
 from app.core.config import settings
 from app.core.database import SessionLocal, engine
-from app.repositories.user import user_repo as user_crud
 from app.models.organization import Organization
 from app.models.user import User
 from app.models.user_organization import UserOrganization
+from app.repositories.user import user_repo as user_crud
 from app.schemas.users import UserCreate
 
 logger = logging.getLogger(__name__)